If Bob is using a lug wrench to change a flat tire and if he

If Bob is using a lug wrench to change a flat tire, and if he needs to apply 58lbf at both ends of his 13 in wrench, what force (in Ibf) would he need to apply to both ends of his friend Bill\'s new/better 19in wrench for the same torque on the lug bolt (within 1 Ibf)?

Solution

Solution :

Lets first calculate the torque that he has applied on 13 in wrench.

We know that

Torque = Force * Distance = 58*13 = 754 lb-in

To get the same torque from his friend Bills 19 in wrench the amount of force that has to be applied is

Force = Torque/Distance = 754/19 = 39.68 lbf = 40 lbf